The present invention relates to a safety device.
It has been proposed to provide various forms of safety device to provide protection for an occupant of a vehicle in the event that an accident should occur. For example, various types of air-bag have been proposed which, depending upon their design, may occupy many different positions within a vehicle relative to a driver. When an air-bag is to be deployed, a gas generator is actuated which generates gas which serves to inflate the air-bag.
In some cases it is desirable for the pressure in the air-bag to be controlled and/or for the air-bag to be “vented”, especially if the occupant has a weight which is not typical, either being relatively heavy or being relatively light, or, alternatively, if the occupant is “out of position” (for example leaning forwardly).
Various proposals have been made for mechanisms to ventilate an air-bag including controlled valves, burst discs and tear-seams which initially seal an outlet air vent. Sophisticated arrangements may include elements such as pressure sensors and/or control units to determine the weight and the position of an occupant and to control the opening of a gas exhaust valve in an optimal manner.
However, there is a requirement for a simple device to control the ventilation of an air-bag which can be used in a flexible manner to provide ventilation at different positions within an air-bag.
Other safety devices also rely on generated gas, such as pre-tensioners, and there is a requirement for a mechanism that may be utilised to control the operation of such safety devices.
Accordingly, to a first aspect of the present invention, there is provided a safety device in the form of a releasable clip, the releasable clip having a first elongate main gripping element, and a second elongate moveable gripping element, the main gripping element having a retaining element to retain one end of the moveable griping element; there being an arrangement to retain the other end of the moveable gripping element in a predetermined position such that the clip may grip a fabric tube or the like between the main gripping element and the moveable gripping element; a mechanism being provided which responds to a supply signal to move the other end of the moveable gripping element to release the grip.
According to another aspect of the present invention, there is provided a safety device configured to be actuated by the supply of gas, the safety device incorporating an outlet vent pipe, the outlet vent pipe being sealed by a releasable clip, the releasable clip having a first elongate main gripping element, and a second elongate moveable gripping element, the main gripping element having a retaining element to retain one end of the moveable gripping element; there being an arrangement to retain the other end of the moveable gripping element in a predetermined position such that the clip may grip the outlet vent pipe or the like between the main gripping element and the moveable gripping element; a mechanism being provided which responds to a supply signal to move the other end of the moveable gripping element to release the grip.
Preferably, the safety device is an air-bag.
Advantageously, the safety device is a pretensioner.
Conveniently, a plurality of said releasable clips are provided, each clip being associated with a respective outlet hose.
Preferably, the releasable clip incorporates a spring initially held in a compressed state and released in response to the signal so as to move the other end of the moveable retaining element.
Advantageously, the main gripping element is in the form of a cylinder, and the other end of the elongate moveable gripping element is configured to fit over or within the cylinder; there being a mechanism to supply gas to the interior of the cylinder in response to the signal to move the other end of the moveable gripping element.
Conveniently, the other end of the moveable gripping element is constituted by a piston movable within the cylinder.
In one embodiment the cylinder has a terminal inward projection to retain the piston in the cylinder.
Preferably, the other end of the moveable gripping element comprises a closure cap dimensioned to close an open end of the cylinder.
Advantageously, the source of gas is a pyrotechnic squib.
Alternatively, the source of gas is a source of compressed gas.
Preferably, the moveable gripping element is provided with an elongate cylindrical gripping portion, one end of which is engaged in a retaining lug provided on the main gripping element.
Advantageously, the main gripping element is in the form of a cylindrical housing, and the moveable gripping element has inclined resiliently mounted walls to engage the exterior of the cylindrical main gripping element.
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will not be described, by way of example, with reference to the accompanying drawings in which: